Historically, man has created structures from masonry blocks. This form of building traces its ancestry from the earliest structures which were piles of rock to contemporary cut stone systems and from sun baked brick to the contemporary trend of utilizing kiln fired bricks and cast cement blocks.
Structures utilizing masonry techniques has become increasingly costly due to the labor and energy involved in transporting the materials to the place of construction and erecting the structure. Masonry items such as brick, cut stone or concrete block are extremely heavy and a significant amount of energy is expended transporting them from their place of origin to the building site. Furthermore, skilled masons are required to lay up the building blocks, whether they be brick, stone or cement and mortar is required to secure the blocks together. Thus the cost of a masonry structure is a function considerable energy expended in transporting the materials and a significant amount of skilled labor in handling the mortar and blocks.
A second contemporary means of constructions consists of fabricating a structure from a framework of sawn boards and covering the framework with siding and plaster board type materials. This latter method of construction is not as sturdy as the block construction and like the block system, does not provide adequate thermal insulation. Furthermore, the wooden structure is prone to fire and insect damage and it requires constant maintenance to prevent deterioration.
The obvious shortcomings of the foregoing building methods led to the improved construction method disclosed in U.S. Pat. No. 4,227,357 on "Construction Blocks" issued to Bobby G. Newsom on Oct. 14, 1980. In this system, skeletal blocks formed from heavy gauge rod or bar stock are provided with straight and hook projections that permit the blocks to be interconnected to form a structure which will receive furring strips or stringers. This concept provides a significant advancement to construction methods but fails to provide adequate strength for certain load bearing wall applications. Furthermore, the rods or bars forming the building blocks do not provide a means whereby wall board or other covering materials may be fastened to the structure. In the construction blocks of U.S. Pat. No. 4,227,357, furring strips are necessary to provide a surface for nailing or adhesively affixing materials to the structural wall.
In the co-pending patent applications, structural building blocks or units were configured as containers but the container function was secondary and therefor the resultant blocks were not as utilitarian as required by a dual function device where each function may be considered primary.